Telecommunication cable

this telecommunication cable contains a very large number of parallel pairs of wires, each capable of transmitting a separate signal

the SS Great Eastern laid the first undersea telecommunication cable

A telecommunication cable is a tool for transmitting data. Early telecommunication cables sent electronic signals over metal wires.

Analog signals, consisting of dots and dashes of static, were used to transmit data in the 19th century, called telegraphy. This required trained operators to manually transmit the signal, and manually transcribe it at the other end. 19th century railroad operators laid continent spanning telegraph cables.

Late in the 20th century techniques were developed to transmit signals, using light, over fibre-optic cables. Laser light is the most useful light for optical cables.